1) Field of the Disclosure
The disclosure relates to time to digital converters. In particular, the disclosure relates to time to digital converters for direct measurement of SET (single event transient) pulse widths.
2) Description of Related Art System on chip (SoC) refers to integrating all components of a computer or other electronic system into a single integrated circuit or chip. SoC may comprise very complex application specific integrated circuits (ASIC), which can be susceptible to ionizing radiation. Ionizing radiation consists of subatomic particles or electromagnetic waves that are energetic enough to detach electrons from atoms or molecules, ionizing them. Such ionizing radiation can cause disruption inside the SoC or integrated circuit or chip. A time to digital converter (TDC) may be utilized as a measuring instrument to determine the pulse width created by the interaction with the ionizing radiation. SoC can experience radiation effects on earth and in space. The TDC can be utilized as a measuring instrument on integrated circuit or chip performance in a control loop to allow the SoC to compensate for the radiation effects.
Known methods exist for different circuit designs which capture the pulse information using delay flip flops and latches. Delay flip flops are integrated circuits that have a clock input and a data input. However, such known methods do not perform processing of the data directly on the integrated circuit or chip. Moreover, such known methods require external data manipulation and external data mining techniques to derive the pulse width information. Such techniques can be redundant, time consuming, costly, and can increase the size of the electronics.
In addition, single event transients (SETs) in combinational logic can be a source for errors in advanced digital integrated circuits or chips. As a result, it is important to know the SET pulse characteristics, and in particular, the SET pulse width, to estimate the vulnerability of a given circuit. Known methods for characterizing SETs exist. Such known methods include measuring pulse width indirectly by calculating a cross-section of events generated from such SETs. However, such known methods require external data mining techniques and involve increased time and expense to carry out.
Accordingly, there is a need for a method using a time to digital converter that provides advantages over known methods and systems.